Press Release

NASA’s X-43A Vehicle Ready for Flight

By SpaceRef Editor
March 24, 2004
Filed under , ,
NASA’s X-43A Vehicle Ready for Flight

NASA has set Saturday, March 27, for the flight of its
experimental X-43A research vehicle. The unpiloted 12-foot-long
vehicle, part aircraft and part spacecraft, will be dropped
from the wing of a B-52 aircraft, boosted to nearly 100,000
feet by a booster rocket and released over the Pacific Ocean to
briefly fly under its own power at seven times the speed of
sound, almost 5,000 mph.

The flight is part of the Hyper-X program, a research effort
designed to demonstrate alternate propulsion technologies for
access to space and high-speed flight within the atmosphere. It
will provide unique “first time” free flight data on hypersonic
air-breathing engine technologies that have large potential

Hyper-X is inherently a high-risk program. No vehicle has ever
flown at hypersonic speeds powered by an air-breathing scramjet
engine. In addition, the rocket boost and subsequent separation
from the rocket to get to the scramjet test condition have
complex elements that must work properly for the mission to be

The $250 million program began with conceptual design and
scramjet engine wind tunnel work in 1996. In a scramjet
(supersonic-combustion ramjet), the flow of air through the
engine remains supersonic, or greater than the speed of sound,
for optimum engine efficiency and vehicle speed. There are few
or no moving parts, but achieving proper ignition and
combustion in a matter of milliseconds proved to be an
engineering challenge of the highest order. After a series of
successful wind tunnel tests, however, NASA is ready to prove
that air-breathing scramjets work in flight.

This will mark the first time a non-rocket, air-breathing
scramjet engine has powered a vehicle in flight at hypersonic
speeds, defined as speeds above Mach 5 or five times the speed
of sound.

Researchers believe these technologies may someday offer more
airplane-like operations and other benefits compared to
traditional rocket systems. Rockets provide limited throttle
control and must carry heavy tanks filled with liquid oxygen,
necessary for combustion of fuel. An air-breathing engine, like
that on the X-43A, scoops oxygen from the air as it flies. The
weight savings could be used to increase payload capacity,
increase range or reduce vehicle size for the same payload.

The X-43A will fly in the Naval Air Warfare Center Weapons
Division Sea Range over the Pacific Ocean off the coast of
southern California.

After booster burnout, the 2,800-pound, wedge-shaped research
vehicle will separate and fly on its own to perform a
preprogrammed set of tasks. After an approximate ten second
test firing of the engine, the X-43A will glide through the
atmosphere conducting a series of aerodynamic maneuvers for up
to six minutes on its way to splashdown.

This will be the second flight in the X-43A project. On June 2,
2001, the first X-43A vehicle was lost moments after release
from the wing of the B-52. Following booster ignition, the
combined booster and X-43A vehicle deviated from its flight
path and was deliberately destroyed. Investigation into the
mishap showed that there was no single contributing factor, but
the root cause of the problem was identified as the control
system of the booster.

For this flight, the B-52 will carry the booster with the
attached X-43A to at least 40,000 feet before its release,
versus the 24,000 feet of the first attempt. The booster will
carry the X-43A research vehicle to approximately the same test
conditions — altitude and speed — as planned for the first

NASA’s Langley Research Center, Hampton, Va., and Dryden Flight
Research Center, Edwards, Calif., jointly conduct the Hyper-X

A video clip, images and additional information about the
project are available on the Internet at:

NASA Television will carry the flight and the post-flight news
briefing live. NASA TV is available on AMC 9, TRANSPONDER 9C,
85 degrees west longitude, vertical polarization with a
frequency of 3880 MHz and audio of 6.8 MHz.

SpaceRef staff editor.